set 1 MCQ Questions & Answers Detailed Explanation

Question : 1

The layer which reflects radio signals back to earth is –

a) Ionosphere

b) Troposphere

c) Ozone layer

d) Stratosphere

Question : 2

What is the composition of nitrolim – a chemical fertilizer?

a) Calcium carbide and carbon

b) Calcium carbide and nitrogen

c) Nitrogen and limestone

d) None of the above

Question : 3

Which of the following statements about polar stratosphere clouds (PSCs) is not correct?

a) Type I clouds are formed at about –77ºC and contain solid HNO₃ . 3H₂O

b) Type II clouds are formed at about –85ºC and contain some ice

c) PSCs do not react with chlorine nitrate and HCl

d) A tight whirlpool of wind called Polar Vortex is formed which surrounds Antarctica

Question : 4

BOD is connected with

a) organic matter

b) microbes and organic matter

c) microbes

d) None

Question : 5

Identify the wrong statement in the following.

a) Greenhouse effect is responsible for global warming.

b) Ozone layer does not permit infrared radiation from the sun to reach the earth.

c) Chlorofluorocarbons are responsible for ozone layer depletion.

d) Acid rain is mostly because of oxides of nitrogen and sulphur.

Question : 6

Which of the following is not involved in the formation of photochemical smog?

a) NO

b) SO₂

c) Hydrocarbon

d) O₃